Railway signaling



Charles H. Lay

Q M B? E. E. PARRILL. ET AL RAILWAY SIGNALING Filed Oct. 17, 1954 THEIR ATTORNEY N S Mm RTLLIQT vmfi w QR J f j N L N N n" gm wm mNW @mw w wfi umv In T. n

Patented Mar. 17, 1936 RAILWAY SIGNALING tion of Pennsylvania Application October 17, 1934, Serial No. 748,668

12 Claims.

Our invention relates to railway signaling, and has for an object the provision of means for controlling signals in such a manner as to insure safe speed of trains over stretches of track where it is desired to have a number of trains follow each other closely, such for example, as, at and near station platforms.

We will describe one form of signaling system embodying our invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a diagrammatic View illustrating one form of signaling system embodying our invention, and Fig. 2 is a diagrammatic view showing a modification of a portion of Fig. 1, and also embodying our invention.

Similar reference characters refer to similar parts in each of the views Referring first to Fig. 1, the reference character K designates a stretch of railway track along Whichtraffic moves in the direction indicated by the arrow. This track is divided by the usual insulated joints to form four track sections AB, B-C, C-D and. D-E. Each section is provided with the usual track circuit comprising a track battery 2 and a track relay designated by the reference character T with a suitable distinguishing suifix. Each section is provided with a signal designated by the reference character S with a suitable distinguishing suffix. As here shown, each of these signals comprises only a stop lamp R and a proceed lamp G, but in actual practice the signals are usually provided with lamps for giving additional indications.

Each signal is provided with a home relay designated by the reference character J with the same suifix as that applied to the corresponding signal. Each signal is controlled by contact 3 of the associated home relay in such manner that the proceed lamp G is lighted when the relay is closed and the stop lamp R is lighted when the relay is open. The circuits for these lamps are obvious from the drawing without detailed explanation and in order to simplify the drawing we have omitted the home relays and circuits for signals SA and SD.

Home relays JB and JC are controlled in part by a slow-acting device M, having a first contact 4 which is closed when and only when the device is in its initial condition, and a second contact 5 a third contact 6 and a fourth contact "I, each of which is closed when and only when the device is in its operated condition. Associated with the slow-acting device M is a normally closed stick relay P.

Home relay JB is provided with a first circuit Which passes from terminal X of a suitable source of current, through front contact 8 of track relay TC, front contact 9 of track relay TB, and the winding of relay JB to terminal of the same source of current; and with a second circuit which passes from terminal X through contact of slow-acting device M, front contact 9 of relay JB and thence through the same path as described for the first circuit.

Home relay JC is provided with a first circuit which passes from terminal X, through front contact Ii! of track relay TD, front contact ll of track relay TC, and the winding of relay JC to terminal 0; and with a second circuit which passes from terminal X through contact 7 of slow-acting device M, front contact H of relay JC and thence through the same path as described for the first circuit.

The slow-acting device M is provided with two operating circuits and a holding circuit. The first operating circuit passes from terminal X through back contact I2 of track relay TA, front contact 53 of track relay TB, and the winding of device M to terminal 0. The second operating circuit for device M is from terminal X, through back contact I4 of track relay TB, front contact I5 of stick relay P, and the Winding of device M to terminal 0. The holding circuit for device M passes from terminal X, through back contact Id of track relay TB, contact 6 of device M, and. the winding of device M to terminal O.

The stick relay P is provided with a pick-up circuit which passes from terminal X, through contact 4 of device M and the winding of relay P to terminal 0; and with a stick circuit which passes from terminal X, through back contact l6 of track relay TB, front contact I! of relay P, and winding of relay P to terminal 0.

From the foregoing description of the circuits it is readily apparent that signal SB assumes the stop position when section B-C or section C-D is occupied and that signal SB is cleared by the closing of contact 5 on the device M, even though section CD is occupied, provided section B-C is unoccupied. Likewise, signal SC assumes the stop position when section C-D or section DE is occupied and signal S. C. is cleared by the closing of contact 1 on the device M even though section DE is is occupied, provided section DE is unoccupied.

It is also apparent that slow-actingdevice M is set into operation when back contact l2 of track relay TA closes. If this device completes its operation so as to close contact 6 before front contact I3 of track relay TB opens, the holding circuit for device M is established by the closing of back contact 14 of track relay TB, and device M is held in the operated condition as long as section BC is occupied. If device M fails to complete its operation before the opening of front contact l3 of track relay TB, the device returns to its initial condition, thus reclosing contact 4 of the device which energizes relay P. The energization of relay P establishes the second operating circuit for the device M through front contact l5 of relay P and back contact M of track relay TB which is already closed.

Referring now to Fig. 2, we have shown a modification of the control circuits for home relay JB in which we have introduced apparatus not responsive to traffic conditions for opening the first control circuit. This apparatus, as here shown, is a contact l8 actuated by a manually operable lever L, either one or both of which may be placed adjacent the track or at some remote point. It is obvious, without detailed description, provided relay TB is closed, that if contact 5 on device M is closed, home relay JB will be energized and signal SB will display the proceed indication although either front contact 8 of track relay TC or contact l8 actuated by lever L might be open.

A contact, similar to 18, actuated by a lever or other means, might also be included in the control circuit for home relay JC, thus providing a method independent of traffic conditions for causing signals SB and SD to display stop indications either separately or simultaneously.

The home relay for signal SA is not shown, but we wish to point out that in actual practice a back contact of the slow-acting device M will usually be introduced into the control circuit for signal SA to insure a restrictive indication is displayed in the event of the device M being improperly held in the operated condition.

While, as here shown, the first control circuits for the home relays extend over two sections of track in advance of the associated signals and the second control circuits include only one section, it is understood that these circuits need not necessarily be limited to the number of track sections shown.

The operation of the system is as follows: Assuming that all of the apparatus is in the condition as shown in the drawing, signals SB and SC indicate proceed because home relays JB and JC are energized.

We will now assume that a first train enters section AB and proceeds through section BC into section CD, thus causing signals SB and SC to display the stop indication, and that a second train enters section AB thereby closing back contact l2 of relay TA to set slow-acting device M into operation. The second train is prohibited from entering section BC before the device has completed its operation since the first control circuit for relay JB is opened by contact 8 of relay TC and the second control circuit for relay JB is not closed until device M completes its operation and contact 5 of the device becomes closed. Thus the second train is forced to consume a given amount of time in section AB in order to provide itself with a proceed indication at signal SB. We will now assume that the first train has advanced to section D-E and the first control circuit for home relay JC is opened by contact ID of track relay TD. The second control circuit for relay JC is closed by contact 1 of the device M so that signal SC assumes the clear indication. Since device M reached its operated condition before the second train entered section BC, the holding circuit for the device is established through back contact E4 of track relay TB and contact 6 of the device thus holding device M in the operated condition while the second train traverses section BC. The second train therefore finds signal SC displaying the proceed indication. It is now apparent that we have provided a meansfor clearing signals SB and SC if the second train consumes a measured amount of time in section AB.

If, however, the time consumed by the second train in passing through section AB is less than the time required for the operation of the slow-acting device M, then when the second train enters section BC, (the first train having proceeded to section D-E), the first operating circuit of device M will be opened at front contact l3 of track relay TB and device M will return to its initial condition. When the device M returns to its initial condition, contact 4 of the device is reclosed and stick relay P is energized thus closing the stick circuit for relay P through its own front contact I! and back contact 16 of track relay TB. The releasing of track relay TB and tablished until contact 1 becomes closed upon the r completion of the second operation of the device M.

From the foregoing description, it is readily apparent that we have provided a single slowacting device M for the two sections AB and BC. This device being controlled in such manner as to permit, when signals SB and SC are caused to indicate stop by the occupancy of the second section in advance of each signal, the clearing of signal SB by a train traversing section AB if and only if such train consumes a measured time interval while occupying section AB, and the clearing of signal SC by a train traversing both sections AB and BC if and only if such train consumes the measured time interval while occupying either section AB or section BC. Assuming that track K is at or near a station platform where it is desirable to permit a number of trains to follow each other closely, it will be seen that.we have provided a simple and effective means for governing the speed of such trains while passing over this portion of the track.

Although we have herein shown and described only one form of apparatus embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is:

1. In combination, four sections of railway track, a slow acting device, means for setting said device into operation when a train enters the first section, a signal for the second section, a signal for the third section, means for causing the signal for the second section to indicate stop if the third section is occupied, means for causing the signal for the third section to indicate stop if the fourth section is occupied, means operating only if said device completes its operation during the passage of the train through the first section for clearing the signal for the second section when the third section is occupied and for clearing the signal for the third section when the fourth section is occupied and for holding said device in its operated condition while the train traverses the second section, means for again setting said device into operation when the train enters the second section if the device has not completed its operation during the passage of the train through the first section, and means for clearing said signal for the third section when the fourth section is occupied if said device completes its operation during the passage of the train through the second section but not if said device fails to complete its operation while such train occupies the second section.

2. In combination, four sections of railway track, a slow-acting device having a second and a third and a fourth contact each closed only when the device is in its operated condition, means for setting said device into operation when a train enters the first section, a signal for the second section, means for causing the signal for the second section to indicate stop when the third section is occupied, means including said second contact for clearing the signal for the second section if the third section is occupied, means including said third contact for holding said device in its operated condition while the train traverses the second section, a signal for the third section, means for causing the signal for the third section to indicate stop when the fourth section is occupied, and means including said fourth contact for clearing the signal for the third section if the fourth section is occupied.

3. In combination, two sections of railway track, a slow-acting device having a contact closed only when the device is in its operated condition, means for setting said device into operation when a train enters the firstsection, a signal for the second section, manually operable apparatus for causing said signal to indicate stop, and means including said contact for clearing said signal if the signal is caused to indicate stop by said apparatus.

4. In combination, three sections of railway track, a slow-acting device having a contact closed only when the device is in its operated condition, means for setting said device into operation when a train enters the first section, a signal for the second section, means responsive to traflic conditions in the third section for causing said signal to indicate stop, apparatus not responsive to trafiic conditions for also causing said signal to indicate stop, and means including said contact for clearing said signal if the signal is caused to indicate stop either by traffic conditions in the third section or by said apparatus or by both.

5. In combination, four sections of railway track, a track circuit including a track relay for each section, a slow-acting device, an operating circuit for said device including a back contact of the track relay for the first section and a front contact of the track relay. for the second section, a holding circuit for said slow-acting device including a contact closed only when the device is in its operated condition and a back contact of said track relay for the second section, a signal for said second section, a first controlling circuit for said signal including a front contact of the track relay for the third section, a second controlling circuit for said signal including a contact closed only when said slow-acting device is in its operated condition, a signal for said third section, a first controlling circuit for said third section signal including a front contact of the track relay for the fourth section, and a second controlling circuit for said third section signal including a contact closed only When said slowacting device is in its operated condition.

6. In combination, four sections of railway track, a track circuit including a track relay for each section, a slow-acting device, a first operating circuit for said device including a back contact of the track relay for the first section and a front contact of the track relay for the second section, a normally closed stick relay, a pick-up circuit for said stick relay including a contact which is closed only when said slow-acting device is in its initial condition, a stick circuit for said stick relay including a back contact of the track relay for the second section, a holding circuit for said slow-acting device including a contact closed only when the device is in its operated condition and a back contact of said track relay for the second section, a second operating circuit for said slow-acting device including a front contact if said stick relay and a back con tact of said track relay for the second section, a signal for said second section, a first controlling circuit for said signal including a front contact of the track relay for the third section, a second controlling conduit for said signal including a contact closed only when said slow-acting device is in its operated condition, a signal for said third section, a first controlling circuit for said third section signal including a front contact of the track relay for the fourth section, and a second controlling circuit for said third section signal including a contact closed only when said slowacting device is in its operated condition.

'7. In combination, three sections of railway track, a track circuit including a track relay for each section, a slow-acting device, a normally closed stick relay, a pick-up circuit for said stick relay including a contact which is closed only when said slow-acting device is in its initial condition, a stick circuit for said stick relay including a back contact of the track relay for the second section, an operating circuit for said slowacting device including a front contact of said stick relay and a back contact of said track relay for the second section, a holding circuit for said slow-acting device including a contact closed only when the device is in its operated condition and a back contact of said track relay for the second section, a signal for said third section, a first controlling circuit for said signal including a front contact of the track relay for the fourth section, and a second controlling circuit for said signal including a contact closed only when said slow-acting device is in its operated condition.

8. In combination, four sections of railway track, a track circuit including a track relay for each section, a slow-acting device, a first operating circuit for said device including a back contact of the track relay for the first section and a front contact of the track relay for the second section, a normally closed stick relay, a pick-up circuit for said stick relay including a contact which is closed only when said slow-acting device is in its initial condition, a stick circuit for said stick relay including a back contact of the track relay for the second section, a holding circuit for said slow-acting device including a contact closed only when the device is in its operated condition and a back contact of said track relay for the second section, a second operating circuit for said slow-acting device including a front contact of said stick relay and a back contact of said track relay for the second section, a signal for said third section, a first controlling circuit for said signal including a front contact of the track relay for the fourth section, and a second controlling circuit for said signal including a contact closed only when said slow-acting device is in its operated condition.

9. In combination, four sections of railway track, a track circuit including a track relay for each section, a slow-acting device, an operating circuit for said device including a back contact of the track relay for the first section and a front contact of the track relay for the second section, a holding circuit for said slow-acting device including a contact closed only when the device is in its operated condition and a back contact of said track relay for the second section, a signal for said third section, a first controlling circuit for said signal including a front contact of the track relay for the fourth section, and a second controlling circuit for said signal including a contact closed only when said slow-acting device is in its operated condition.

10. In combination, three sections of railway track, a track circuit including a track relay for each section, a slow-acting device, an operating circuit for said device including a back contact of the track relay for the first section and a front contact of the track relay for the second section, a

signal for said second section, a first controlling circuit for said signal including a manually operable contact and a front contact of the track relay for the third section, and a second controlling circuit for said signal including a contact closed only when said slow-acting device is in its operated condition.

11. In combination, three sections of railway track, a slow-acting device, means for initiating the operation of said device when a train enters the first section, means for holding said device in its operated condition while the train traverses the second section if the device completes its operation during passage of the train through the first section but not if the device fails to complete its operation while such train occupied the first section, means for again setting said device into operation when the train enters the second section if the device has not completed its operation during passage of the train through the first section, and signaling means for the second and third sections controlled in part by said device.

12. In combination, three sections of railway track, a slow-acting device, means for initiating the operation of said device when a train enters the first section, a normally closed stick relay, means for opening said relay When the operation of said device is initiated, means for closing said relay when the train enters the second section if and only if the operation of said device is not completed during passage of the train through the first section, means for again initiating the operation of said device when the train enters the second section if and only if said relay remains closed, and signaling means for the third section controlled in part by said device.

EASTON E. PARRILL. CHARLES H. LAY.

CERTIFICATE OF CORRECTION.

Patent No. 2,054,535. March 17, 1956.

EASTON E. PARRILL, ET AL.

It is hereby certified that error appears in the printed, specification of the above numbered patent requiring correction as follows:

Page 3, second column, line 31, claim 6,

for "if" read of; and line 36, same claim, for "conduit read circuit; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of April, A. D. 1936.

Leslie Frazer (Seal) Acting; Commissioner cf Patents. 

